Conical imaging mirrors for high-speed x-ray telescopes.

The conical x-ray imaging mirror represents the long focal length limit of a Wolter type I grazing incidence mirror, in which the curved surfaces have been replaced by simple cones. When many thin-walled cones are nested, such a mirror affords the relatively high aperture filling factor needed for telescopes well suited to broadband x-ray astonomy. A conical mirror also features a constant spatial resolution across the field of view and can be designed to have an arbitrarily high intrinsic spatial resolution. We describe the spatial resolution and filling factor of conical optics as a function of various design parameters as characterized using a Monte Carlo ray tracing procedure.